A l e x and er Fl e mi n g

A l e x and er Fl e mi n g H N O O N S OH O Stap Fig. . Discovery of penicillin Hypersensitivity reaction is a major problem with the use of penicillin, resulting in nausea, vomiting, wheezing and ultimately cardiovascular collapse. To check the sensitivity reaction, doctors use a needle to prick the forearm of the patients to give a weak dose of penicillin. An itchy red region in the forearm is an indication that the patient is allergic to penicillin. This test is important before administration of penicillin to a patient. Tetracycline is a broad spectrum bacteriostatic antibiotic (antibiotics that limit the growth of bacteria) that inhibits microbial protein synthesis. Chlortetracycline is the first antibiotic of this group, isolated from the cultures of Streptomyces aureofaciens . Streptomycin is a broad spectrum antibiotic isolated from the actinomycetes, Streptomyces griseus . It is bactericidal against both gram positive and gram negative bacteria, especially against Mycobacterium tuberculosis . Antibiotics, such as erythromycin, chloromycetin, griseofulvin, neomycin, kenamycin, bacitracin, etc., are also isolated as microbial products.